JoeS wrote:Without a rate restructure specifically pertinent to DCQC high-demand-power car charging, I think it's tough to make a profit being a DCQC car-charging supplier.

In wandering around some of Tesla's recently-installed Superchargers, I've spied sizeable battery banks - undoubtedly intended to take peak loads and ensure that the facility doesn't get into the demand charging region. Incidentally, the local high school, in addition to installing a massive solar array covering their parking lot, also installed a huge battery bank for demand charge mitigation. Evidently the math showed a very short payback timeframe.

That’s a good find, I suspected the rates are obscene behind the scenes. All the L3 chargers here are similarly priced, causing some outrage as a lot of them were government subsidized.

I’ve seen several solar powered stations here in Canada, that might be the way if rates aren’t improved.

ChrisEV wrote:I’ve seen several solar powered stations here in Canada, that might be the way if rates aren’t improved.

I don't see any way solar alone will ever help to improve L3 charging rates. Unless a LARGE solar array could be used to charge a LARGE battery pack so the demand for LARGE amounts of current in a hurry won't impact the cost of the electricity, there's nothing there to moderate the peak demand for juice from the utility

Even then, the LARGE cost of setting up the big solar array and the big battery bank would certainly make for a need for higher charges to amortize the big front end expenditures. I think Tesla got around the large expenses of their Supercharger network by adding a few thousand to the cost of every car they were selling - When they began offering more mid-priced cars, access to the Supercharger network was no longer free

In my humble opinion, the eventual use of most EV's will be determined by the practical size of the battery vs the intended use of the vehicle. You *need* 300 or 500 or even 750 miles of range, you can build an EV which will do that - The downside is that for most uses, you're lugging around many hundreds of pounds of extra weight for a huge battery pack that you very seldom need, which reduces the efficiency of the vehicle. For 90% or so of average needs a car with 100 or so miles of range can pretty much do what you need. Make it small and nimble, easy to park, easy to get into and out of and add the ability to fold down seats so you can carry a good bit of cargo when needed and you've pretty much got it all . . . . IMO

Don wrote:...For 90% or so of average needs a car with 100 or so miles of range can pretty much do what you need. Make it small and nimble, easy to park, easy to get into and out of and add the ability to fold down seats so you can carry a good bit of cargo when needed and you've pretty much got it all . . . . IMO

Don, agree with you. Talking with both Tesla and Bolt owners I've come to realize that the major selling point to them was 'range' and which has nothing to do with the reality of how they use their cars. The two (female) Tesla owners in my exercise class simply drive the cars locally and are fearful of taking even a short excursion outside the Bay Area (Lake Tahoe is beyond their comprehension) and one hasn't even tried a Supercharger yet! At an environmental presentation last week I was talking with new Bolt owner who finally bought the car because he said it was the first EV that finally met his needs ... he lives in the hills and has a 30-mile one-way daily commute WITH charging at work, and, no, he "wouldn't dare" take it on a longer trip - AND he didn't even know if his car has CCS. Go figure...

Can't help but think that dealers selling PHEVs are responsible for at least some of this fear-mongering.

When I tell people of my cross-country Tesla trips you'd think I was climbing Mt. Everest or something...

Back on topic, whenever I put PlugShare up on my iPad to show off the existing charging infrastructure, most people are amazed and had no idea of its existence! Perceptions, again. Never mind that they don't know what they're looking at, but simply having all those green and orange icons scattered all over the local map is compelling to them and an 'aha' moment. IMO, future public EV charging should be focused on highway DCQC, whereas multi-unit dwelling charging support needs both a carrot and a stick for much more rapid implementation than we've had to date.

JoeS wrote:Demand charges are hideous - for example, PG&E's demand rate is $18.64 per kWh (that's right, NOT 18¢/kWh!), and as I understand it this then lasts through the entire billing cycle.

tsk, tsk, Joe- probly a typo, but I'll take you to task for perpetuating some of the misunderstandings around demand charges. Demand is instantaneous power measured in kW, similar to throttle position, while consumption is energy consumed over time, in kWh (akin to distance travelled). Speed vs miles travelled is another analogy. So just as you can get a speeding ticket yet have a very low average trip speed, demand spikes are very expensive even though a DCFC station may use less energy than some houses over the course of a day (which see no demand charges).

In my day job as a school district energy manager, instantaneous demand ranges between 100 kW and 1200 kW for a high school, and high demand is only experienced during less than 3% of our operating time, but makes up at least 40% of the electric cost! So even though a grid-tied battery that is only called on for offsetting brief demand spikes will actually add to total energy consumed due to charge/discharge losses, it can be quite profitable to buy that energy in periods of low demand and sell during high demand, as evidenced by TESLA's big South Australian project.https://www.sciencealert.com/south-australia-tesla-battery-earns-million-neoen-company?perpetual=yes&limitstart=1

I think there's a future for DCFC stations with big batteries that are also in the grid frequency regulation and peak power market. Better yet, if they're on the customer side of a big meter attached to a factory, shopping mall, hospital or school, then the battery will produce savings at retail rather than wholesale cost while also providing for emergency power backup rather than expensive and less-reliable generator sets. And then of course, for extended emergency operation, that battery needs to be attached to solar, and off we go into a positive feedback loop.

Back to the main topic, I think that a lot of the new VW and State public charging infrastructure will be underutilized and thought it was because the new stations would mainly serve as insurance and soothe the range anxiety of potential buyers, but according to Joe's experience, I should go back into depression because EVen the existing EV drivers are ignorant of the existing EV infrastructure!

jray3 wrote:Demand is instantaneous power measured in kW, similar to throttle position, while consumption is energy consumed over time, in kWh (akin to distance travelled). Speed vs miles travelled is another analogy. So just as you can get a speeding ticket yet have a very low average trip speed, demand spikes are very expensive even though a DCFC station may use less energy than some houses over the course of a day (which see no demand charges).

In my day job as a school district energy manager, instantaneous demand ranges between 100 kW and 1200 kW for a high school, and high demand is only experienced during less than 3% of our operating time, but makes up at least 40% of the electric cost!

Isn't that because once a demand meter is bumped up to a certain peak demand, all future electricity is priced at that demand level until the end of that billing cycle?

Even a few minutes use at the 1200Kw level you specified causes the later, lower 100Kw uses to be charged at the same rate as the 1200Kw rate?

If you had a large enough battery bank, you could charge it at the 100Kw rate (or better yet at the even lower overnight TOU rates) and then let the battery bank supply the brief 1200Kw surges

![/quote]Isn't that because once a demand meter is bumped up to a certain peak demand, all future electricity is priced at that demand level until the end of that billing cycle?Don[/quote]

Practices vary a lot between utilities and different states. I don't know a term for what Don described, but a similar concept is the Demand Ratchet, which can set demand charges that continue forward for up to a year, regardless of how low your demand falls during that year. Each time you hit or exceed that high demand paint, the clock is set for another 12 months of charges going forward. The reasoning is that the utility has to build and maintain infrastructure to support that high level of demand even if you're not using it often.

I'm lucky to have a pretty straightforward system. We pay demand charges for the highest demand averaged across a single 15 minute period in the month, and that demand charge is unrelated to the energy charge per kWH, regardless of when consumed (no Time of Use pricing). If we improve operations, the savings materialize within a month, instead of waiting up to a year for a full return on the investment.

Here's a more detailed description from the WSU Energy Extension Service:

Ratchet Demand ChargeSome utilities have a ratchet charge on the demand. The highest monthly demand experienced for the year becomes your annual peak. The annual peak is then used to ratchet the monthly demand peaks for the next 11 months. For example, the minimum demand charge for any month is 60 percent of the highest demand in the preceding 11-month period. Demand is a very important target for reduction if your utility has a ratchet clause on the demand.

Examples of a ratchet demand charges:

Your demand in December is 800 kW, and you pay $5 per kWYou will pay a $4,000 demand charge for DecemberThe following June, the demand meter reads 150 kW. You are charged $2,400 rather than $750 (60 percent of 800 kW is 480 kW, times $5 per kW, equals $2,400)This increase in demand cost of $1,650 is due to the ratchet clause in the rate schedule. This same ratchet will be charged in all warm months, even when demand is low.

Don wrote:...For 90% or so of average needs a car with 100 or so miles of range can pretty much do what you need. Make it small and nimble, easy to park, easy to get into and out of and add the ability to fold down seats so you can carry a good bit of cargo when needed and you've pretty much got it all . . . . IMO

Back on topic, whenever I put PlugShare up on my iPad to show off the existing charging infrastructure, most people are amazed and had no idea of its existence! Perceptions, again. Never mind that they don't know what they're looking at, but simply having all those green and orange icons scattered all over the local map is compelling to them and an 'aha' moment. IMO, future public EV charging should be focused on highway DCQC, whereas multi-unit dwelling charging support needs both a carrot and a stick for much more rapid implementation than we've had to date.

There’s a lot of ignorance and misconception about EV’s so a lot comes from that. Everyone I talk to gets wide eyed about my EV as they had no idea how it works.

Most people don’t really keep track of their daily mileage either.

From all my conversations about EVs with people it’s in the context of replacing their primary ICE vehicle which can go a few hundred km’s on a full tank of gas. Nobody worries about running out of gas on a trip because you can go very far, gas stations are everywhere and it takes minutes to fill up.

It’s all about convenience. And that’s why Tesla is leading because their cars are closest to mimicking ICE cars in terms of range and availability/convenience/speed of Superchargers.

My I-MIEV is perfect for what I got it for which is commuting and doing shopping trips around town but I’ll almost never take it on a long trip beyond it’s range.

I’m on a short 160km trip out of town right now and I wouldn’t dare take the I-MIEV. Given the 29F temperature, lack of L3 chargers on the route and a lot of uphill driving plus wind I probably wouldn’t have made it to the few L2 chargers available.

Don wrote:. . . . . at any rate, that pretty much explains why DCQC is so ridiculously expensive in so many places

Don

There’s several free L3 chargers here in town, most notably IKEA. I wonder how that long that will last.

Even Tesla owners use them which causes some anger(go to a supercharger!).

JoeS wrote:Demand charges are hideous - for example, PG&E's demand rate is $18.64 per kWh (that's right, NOT 18¢/kWh!), and as I understand it this then lasts through the entire billing cycle.

tsk, tsk, Joe- probly a typo, but I'll take you to task for perpetuating some of the misunderstandings around demand charges. Demand is instantaneous power measured in kW, similar to throttle position, while consumption is energy consumed over time, in kWh (akin to distance travelled). ..In my day job as a school district energy manager, instantaneous demand ranges between 100 kW and 1200 kW for a high school, and high demand is only experienced during less than 3% of our operating time, but makes up at least 40% of the electric cost! ..

jray3, you're right, in reading the PG&E table I missed the 'demand' column being $/kW and not $/kWh! My bad, with apologies, and I'd love to have a separate discussion with you about this whole subject the next time we visit.

Back on topic, jray3's example shows the disproportionate penalty being paid for such 'demand' charges. Since multiple DCQC stations at one location may well trigger such demand charges, the legislative approach could be to exempt EV DCQC stations from such a tariff (if that's the proper word), or the pragmatic approach would be to install batteries to ensure the demand peak power point is never exceeded. It would not be acceptable to throttle back all the cars charging to keep this limit from being exceeded. Along this line, two Tesla superchargers normally share a common input (the stations are labeled "1A" & "1B", "2A" & "2B, etc.) so when a Tesla plugs into a station number that is already being used by another car, then the power to both is reduced - as I understand it, with priority given to the car that's already charging. During my cross-country trip I paid a lot of attention to this and was usually successful in avoiding power sharing.Edit:ChrisEV, would you have taken that 160km winter trip in the i-MiEV if you had free CHAdeMO L3 spaced every 65km along the way?

I suspect that free (subsidized) L3 charging will gradually disappear. Given some of the present L3 cost structure (e.g., EVgo), at today's gasoline rates this makes long-distance BEV travel not only somewhat painful (timewise with <50kW stations) but also uncompetitive financially with ICE (except for Tesla).